The law, which bans 41 dog breeds within Beijing's city limits, has been in effect since 1994, but has only been seriously enforced this year, NBC News reported.
"This is nonsense. How can they decide whether a dog is vicious?" said 26-year-old Yao Wang, who, along with her English sheepdog Guoguo, has moved four times in the last three months to stay ahead of the law.
The director of the Chaoyang District Office of Dog Management, who was identified only by his surname, Liu, said he was unsure why the law is now being strictly enforced.
"We don't know either. We are here to carry out the job," Liu said.
Mary Peng, co-founder of the International Center for Veterinary Services in Beijing, said a major factor in the law's enforcement was that in 2012, 13 people in Beijing died from rabies, more than doubling the previous year's figure.
"In China, only [10 percent to 20 percent] of dogs have been vaccinated [for rabies], compared to more than 70 percent in the U.S.," Peng said.
Peng said safety issues have little to do with a dog's size, and that many small breeds are more likely to bite people that larger breeds like golden retrievers.